1. Field of the Invention
The present invention relates to a method and apparatus for inserting a plate nut into a blind cavity, and more particularly to a process for inserting a plate nut through one of its fastening holes.
2. Description of the Prior Art
In the course of any mechanical assembly occasions arise in which a fastener is threaded into a nut that is inaccessible. As a result various plate nuts or holding devices have been devised which in one manner or another are retained in the inaccessible cavity holding the nut in a position while it is threaded by the fastener. In the instances where the necessity for blind fastening is anticipated the foregoing techniques have been adequate and no further improvement was therefore required.
Occasionally, however, unanticipated events require access to a blind cavity in order to position a nut therein for fastening. In the past various tools have been devised which, in one manner or another, are useful in manipulating a nut into a cavity that is difficult to reach. Examples of such prior solutions may be found in U.S. Pat. No. 2,664,771 to Elliott, U.S. Pat. No. 3,507,172 to Smith, U.S. Pat. No. 2,594,321 to Leftwich and U.S. Pat. No. 5,727,431 to Wivagg. While suitable for the purposes intended each of the foregoing devices requires some form of access to the position at which the nut is to be placed.
In those instances where rear access is completely limited few tooling solutions are available in the art. Accordingly a technique for aligning a nut inside a blind cavity is extensively sought and it is one such technique that is disclosed herein.
Accordingly it is the general purpose and object of the present invention to provide a technique for positioning threaded plate nuts in a blind cavity.
Other objects of the invention are to provide a method and a tool for installing a threaded fastener into a fully inaccessible structure.
Further objects of the invention are to provide a method for installing and affixing a plate nut from the fastener side of a structure.
Briefly, these and other objects are accomplished within the present invention by providing an elongate plate nut that includes the threaded opening to be engaged by the fastener and also a further opening by which the plate nut may be secured to the adjacent structure. In section, the plate nut may be rounded to a semicircular form for insertion through an enlarged drilling in the structure. This drilling may be chamfered for receipt of an insert after the plate nut is installed, which is then used to fasten the plate nut in place.
A hinged tool may be utilized in the course of insertion of the plate nut and once positioned through the enlarged drilling the other plate nut opening may then serve to hold the plate in place. The insert then placed into the enlarged drilling is captured by a plate holding fastener that is then threaded into the further opening therein.
In this manner a repair can be effected over a blind structural enclosure by forming a chamfered drilling in the structure dimensioned to the plate nut section, then inserting the plate nut therethrough and thereafter holding the plate nut in place through the opening that has been formed for the structural repair. Once so positioned the plate nut is then fixed in place an insert in the chamfered drilling which is then captured by a plate securing fastener.